WO2006019181A1 - Procédé de mesure de forme, dispositif de mesure de forme et dispositif générateur de lumière à peigne de fréquence - Google Patents

Procédé de mesure de forme, dispositif de mesure de forme et dispositif générateur de lumière à peigne de fréquence Download PDF

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Publication number
WO2006019181A1
WO2006019181A1 PCT/JP2005/015309 JP2005015309W WO2006019181A1 WO 2006019181 A1 WO2006019181 A1 WO 2006019181A1 JP 2005015309 W JP2005015309 W JP 2005015309W WO 2006019181 A1 WO2006019181 A1 WO 2006019181A1
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WIPO (PCT)
Prior art keywords
optical
frequency comb
mirror
light
frequency
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PCT/JP2005/015309
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English (en)
Japanese (ja)
Inventor
Takashi Kurokawa
Yousuke Tanaka
Tatsutoshi Shiota
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National University Corporation Tokyo University Of Agriculture And Technology
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Application filed by National University Corporation Tokyo University Of Agriculture And Technology filed Critical National University Corporation Tokyo University Of Agriculture And Technology
Priority to JP2006531931A priority Critical patent/JP4543180B2/ja
Priority to DE112005001980T priority patent/DE112005001980T5/de
Priority to US11/659,951 priority patent/US7440112B2/en
Publication of WO2006019181A1 publication Critical patent/WO2006019181A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
    • G01B11/2441—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures using interferometry
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A61B5/0062—Arrangements for scanning
    • A61B5/0066—Optical coherence imaging
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
    • A61B2562/02—Details of sensors specially adapted for in-vivo measurements
    • A61B2562/0233—Special features of optical sensors or probes classified in A61B5/00

Definitions

  • Shape measuring method shape measuring device, and frequency comb light generator
  • the present invention is capable of observing the epidermis and the like up to a deep location with high spatial resolution.
  • the present invention relates to a measuring method and shape measuring device, and a frequency comb light generating device which can generate a large number of frequency combs with a variable frequency interval by a simple configuration and which can operate stably.
  • FIG. 11 (A) shows a conventional optical coherence tomography.
  • the optical coherence tomography 8 is a low-coherence light source 8 1, a condenser lens 8 2, a half mirror 8 3, a reference mirror 8 4, and a reference mirror moving
  • the actuator 8 5 the objective lens 8 6, the detection lens 8 7, the photodetector 8 8, and the control computer 8 9 are provided.
  • the components of the optical coherence tomography 8 except for the low-coherence light source 8 1 and the control computer 8 9 constitute the optical interferometer.
  • a low-coherence light source 81 a light source with a wide spectrum such as LED or SLD (Super Luminescent Diode) is used. As shown in Fig. 11 (B), the wavelength spectrum is broad (for example, several 10 nm or more).
  • the low coherence light source 8 1 is controlled by a control signal A 1 from the computer 89.
  • the low-coherence light source 8 1 is collimated by the condenser lens 8 2 and is emitted to the half mirror 8 3.
  • the half mirror 8 3 divides the light incident from the condensing lens 82 into two parts, emits one to the reference mirror 84, and emits the other toward the object to be measured O through the objective lens 86.
  • the half mirror 8 3 combines the reflected light from the reference mirror 8 4 and the reflected light from the reflection point inside the object to be measured O, and passes through the detection lens 8 7 to the photodetector 8 8. Exit.
  • the reflected light from the object to be measured O includes light reflected from the surface, light reflected from a shallow position inside, light reflected from deep inside, and the like.
  • the reflected light whose interference is observed is L from the half mirror 83 to the reference mirror 84.
  • the coherence length is L. If ', the distance from the half mirror 8 3 is only the reflected light from the surface existing at the position of (L. Sat / 2). Therefore, if the distance from the half mirror 8 3 to the reference mirror 8 4 is changed by the actuator 85 (controlled by the control signal A 2 from the computer 8 9), the distance corresponds to that distance. Only the reflected light from the reflecting surface can be selectively detected. As a result, the reflectance at an arbitrary position inside the object to be measured O can be obtained by the computer 89, and the distribution of the obtained reflectance is visualized on a display (not shown). It becomes possible to visualize the structural information inside the object to be measured O. Disclosure of the invention
  • the output of the low-coherence light source 8 1 in Fig. 11 (A) has a wide spectrum as described above (see Fig. 11 (B)). Therefore, optical coherence tomography 8 provides a high spatial resolution in the depth direction, but the light intensity is low and the utilization efficiency is poor, so only a weak output can be obtained. It is impossible to observe the place. Moreover, the observation takes time and the reference mirror is movable, so the reliability is not necessarily high.
  • optical coherence tomography is also being considered to increase the spatial resolution.
  • this optical coherence tomography is not suitable for use in clinical settings because of its large size and high price.
  • the conventional frequency comb light generator 9 shown in FIG. 1 2 (A) includes a laser light source 9 1 and an optical resonator 9 2.
  • the optical resonator 9 2 is composed of an optical modulator 9 2 2 formed on an LN (Li N b O 3 : lithium niobate) substrate 9 2 1 and mirrors M 0 1 and M 0 2. .
  • the output light (angular frequency ⁇ ) of the laser light source 9 1 is modulated by the modulation signal RF 0 in the optical resonator 92 to be frequency shifted. After this, mirror ⁇ 0 1, MO 2 Thus, the light is repeatedly reflected and modulated repeatedly, and laser light (modulated light ML) as shown is output from the optical resonator 92.
  • This modulated light ML is shown as a frequency component F E in FIG. 12 (A) and discretely includes a number of frequency components as shown in the spectrum diagram of FIG. 12 (B). As shown in these figures, the angular frequency is ⁇ . It is distributed on the high frequency side and the low frequency side.
  • the object of the present invention is to use a frequency comb light generator with a variable frequency comb frequency interval as a light source, and to measure the shape of the epidermis etc. up to deep locations and with high depth spatial resolution. It is an object of the present invention to provide a method and a shape measuring apparatus such as optical coherence tomography. Another object of the present invention is to provide a frequency comb light generator that can generate a large number of frequency combs and has a stable operation with a simple configuration and a variable frequency comb frequency interval. . In order to achieve the above-described object, the present invention provides a front wheel steering control device that improves the steering stability of a vehicle.
  • First calculating means for calculating the vehicle's current rate, in which the slip angle across the center of gravity of the vehicle body is always 0 based on the handle angle and vehicle speed read by the reading means;
  • Control means for performing steering control of the vehicle based on the target actual front wheel steering angle calculated by the second calculation means
  • the target front wheel actual rudder angle is obtained by superimposing a feed forward actual rudder angle proportional to the handle angle of the vehicle and a feed forward actual rudder angle obtained by adding a first-order lag element to the differential value of the steering wheel angle. Can be calculated.
  • FIG. 1 is a diagram showing a first embodiment of the frequency comb light generator of the present invention.
  • Fig. 2 (A) is a diagram showing a first example of the optical modulator of the frequency comb light generator of Fig. 1, (B) is a perspective view of the frequency comb light generator of (A), ( C) is a spectrum diagram of the output light from the optical modulators (A) and (B).
  • FIG. 3 (A) is a diagram showing a second example of the optical modulator of the frequency comb light generating device of Fig. 1, and (B) is the spectrum of the output light of the optical modulator of (A).
  • Fig. 4 is a diagram showing an example in which an optical fiber amplifier is provided in the frequency comb light generator shown in Fig. 1.
  • FIG. 5 is a diagram showing a second embodiment of the frequency comb light generator of the present invention.
  • Figure 6 shows the basic configuration of optical coherence tomography of the present invention, and (B) shows the output of the frequency comb light generator in (A). It is a spectrum diagram of light.
  • Fig. 7 A detailed spectrum diagram of the output light of the light source for explaining the operation of the frequency comb light generator in Fig. 6 (A).
  • FIG. 8 is an explanatory diagram of a first embodiment of optical coherence tomography according to the present invention.
  • FIG. 9 is an explanatory diagram of a second embodiment of optical coherence tomography according to the present invention.
  • FIG. 10 is a diagram showing a single-loop frequency comb light generator that can also be used as the optical coherence tomography frequency comb light generator of FIGS. 6 and 9.
  • FIG. 10 is a diagram showing a single-loop frequency comb light generator that can also be used as the optical coherence tomography frequency comb light generator of FIGS. 6 and 9.
  • FIG. 10 is a diagram showing a single-loop frequency comb light generator that can also be used as the optical coherence tomography frequency comb light generator of FIGS. 6 and 9.
  • Fig. 11 (A) is a diagram showing conventional optical coherence tomography, (B) is a frequency spectrum diagram of a low coherence light source Fig. 12: (A) is a conventional frequency comb light It is a figure which shows a generator, (B) is a frequency spectrum figure of the output of the conventional frequency comb light generator.
  • FIG. 1 is a diagram showing a first embodiment of the frequency comb light generator of the present invention.
  • a frequency comb light generator 1 includes a laser light source 1 1, a circulator 1 2, an optical resonator 1 3, and a comb interval adjuster 1 4.
  • the laser light source 11 can output laser light (center angular frequency ⁇ 0 ) in a wavelength band (for example, 1.2 to 1.6 ⁇ ) having high transmittance in the living body.
  • the modulation signal LM is input to the laser light source 1 1, which causes the center frequency ⁇ .
  • Can have a predetermined width for example, a width from the number 1 0 0 ⁇ to the number GH z).
  • the circulator 1 2 is provided between the laser light source 1 1 and the optical resonator 1 3, and the laser light source 1 1 is connected to the first port P 1 1 with an optical fiber F 1 1 (polarization maintaining fiber)
  • the optical resonator 13 is connected to the second port P 1 2 via the optical fiber F 1 2 (polarization-maintaining fiber). Incident light from the first port P 1 1 is emitted from the second port P 1 2, and incident light from the second port P 1 2 is emitted from the third port P 1 3. .
  • This third port P 13 serves as an exit for the frequency comb light OFC described later.
  • the optical resonator 13 uses the laser light (center angular frequency ⁇ ) output from the laser light source 11 1 as a seed to generate the frequency comb light OFC.
  • the optical modulator 1 3 1 2 mirrors M il and M 1 2 are provided.
  • the comb interval adjuster 14 is a modulation signal generator that changes the modulation signal applied to the modulation electrode of the optical resonator 1 3, and changes the angular frequency interval ⁇ of the frequency comb by changing the modulation frequency. (Sweep angular frequency interval ⁇ ).
  • the first mirror M il is provided on the circulator 12 side of the optical modulator 13 1, and the second mirror M l 2 is provided on the side opposite to the first mirror M il with a predetermined length (mirror).
  • the distance between the mirror M 1 2 and the mirror M 1 1 is L through the optical fiber F 1 3 (single mode (SM) fiber).
  • the second mirror M l 2 is a Faraday one-turn mirror.
  • a single mode fiber is Causes a change in polarization state.
  • the polarization plane is rotated 45 ° at the time of incidence and at the time of reflection by a Faraday rotation mirror (second mirror M 1 2) provided at the end of the optical fiber F 1 3. (That is, the polarization state finally rotates 90 ° with respect to the original light).
  • the change in polarization state that occurs in the optical fiber F 1 3 is accurately compensated.
  • the length of the optical fiber F 1 3 is such that the distance L between the first mirror M l 1 and the second mirror M 1 2 is an integer (m) times the half wavelength ( ⁇ / 2). It is set as follows.
  • the optical modulator 1 31 includes an LN (L i N b 0 3 : lithium niobate) substrate 1 3 1 1 and an optical waveguide 1 3 1 formed on this substrate. 2 and a modulation electrode 1 3 1 3.
  • Fig. 2 (A) also shows the mirrors M il and M l 2
  • Fig. 2 (B) shows the oscillator OC and termination resistor R as the modulation drive circuit.
  • laser light (exp (io). T) is incident on the optical modulator 1 3 1, and the modulation electrode 1 3 1 3 is connected to the oscillator OC.
  • RF modulation signal
  • the angular frequency is ⁇ . Centered on the side of the frequency and It represents the frequency comb distributed on the lower side.
  • a phase shifter (not shown) can be provided to adjust ⁇ .
  • Figure 2 (C) is a spectrum diagram of Eq. (3).
  • N frequency combs of N frequency (N is an odd number) of ⁇ are distributed in the band of (N-1) ⁇ . It is shown.
  • the intensity of each frequency component is shown to be uniform. Actually, the intensity varies, but it does not greatly affect detection in optical coherence tomography, etc., which will be described later.
  • FIG. 3 (A) A second example of the optical modulator 1 3 1 is shown in FIG.
  • the optical modulator 1 3 1 in Fig. 3 (A) is a Mach-Zehnder waveguide type optical modulator.
  • the optical waveguide 1 3 1 2 and the modulation electrode for modulation 1 3 1 3 is formed on the LN substrate 1 3 1 1, and the modulation electrode 1 3 1 3 is the electrode EP 1 formed on one optical path (arm) and the other optical path (arm) ) Electrodes EP 2 and EP 3 formed in the above, and force.
  • Fig. 3 (A) laser light (represented by e X p (i ⁇ . T)) is incident on the optical modulator 1 3 1, and the modulation signal RF 1, ⁇ 1 sin Q is applied to the electrode EP 1.
  • the electrode ⁇ ⁇ 2 has a modulation signal R F 2
  • bias DC is applied to electrodes ⁇ ⁇ 3.
  • a DC signal is given to the bias DC so that the phase of the light propagating through the two arms is 0 or ⁇ .
  • Each signal is given to each electrode EP1, EP2, EP3, and a DC signal with the phase of the light propagating through the two arms as ⁇ is given to the bias DC.
  • the modulated laser beam e (t) is expressed by equation (4) using the Bessel function.
  • equation (5) is obtained.
  • Equation (5) represents an odd-order frequency comb.
  • This frequency comb has an angular frequency of ⁇ , as shown in the spectrum diagram of Fig. 3 (B). It is distributed on the high frequency side and the low frequency side with a comb spacing of 2 ⁇ .
  • Figure 3 ( ⁇ ) Shows how Enomoto ( ⁇ is an odd number) frequency comb with a comb interval of 2 ⁇ is distributed in the band of 2 ( ⁇ — 1) ⁇ .
  • the intensity of each frequency component is shown to be uniform, but even if there is a variation, it can be applied to optical coherence 'tomography' as described in Fig. 2 (C). Has no significant effect.
  • the optical modulator 1 3 1 in Fig. 3 (A) is compared to the optical modulator 1 3 1 in Fig. 2 (A).
  • the comb interval is doubled to 2 ⁇ , and the bandwidth can be doubled.
  • FIG. 5 is a diagram showing a second embodiment of the apparatus.
  • the frequency comb light generator 2 includes a laser light source 2 1, an isolator 2 2, an optical resonator 2 3, and a comb interval adjuster 2 4.
  • the laser light source 2 1 can output laser light (center angular frequency ⁇ ) in a wavelength band with high transmittance in the living body.
  • the isolator 22 is provided between the laser light source 2 1 and the optical resonator 2 3, and the laser light source 2 1 is connected to the optical fiber F 2 1 (polarization maintaining) in the first port ⁇ 2 1.
  • the optical resonator 23 is connected to the second port ⁇ 22 via the optical fiber F 2 2 (polarization maintaining fiber).
  • the optical resonator 2 3 generates a frequency comb light FC using the laser light (center angular frequency ⁇ ) output from the laser light source 2 1 as a seed.
  • the optical modulator 2 3 It has 2 mirrors 1 2 1 and ⁇ 2 2 and optical fiber amplifier 2 3 2.
  • the comb interval adjuster 24 is a modulation signal generator that changes the modulation signal applied to the modulation electrode of the optical resonator 23, and changes the comb interval ⁇ by changing the modulation frequency (angular frequency interval). ⁇ can be swept).
  • the first mirror M 2 1 is provided on the isolator 2 2 side of the optical modulator 2 31, and the second mirror ⁇ 2 2 is on the opposite side of the first mirror ⁇ 2 1, It is connected via a length L optical fiber F 2 3 (polarization-maintaining fiber).
  • the above-described optical fiber amplifier 2 3 2 is a polarization maintaining fiber amplifier.
  • the second mirror ⁇ 22 serves as an exit for the frequency comb light OFC described later.
  • the length of the optical fiber F 2 3 is the same as in the first embodiment.
  • the distance L between the first mirror 1 ⁇ 2 1 and the second mirror V 2 2 is V of half wavelength ( ⁇ 2). It is set to be an integer (m) multiple. Where the distance L is
  • optical modulator 2 3 one having the same configuration as that of the optical modulator 1 3 1 shown in FIGS. 2 (A) and 3 (A) can be used.
  • optical coherence tomography 4 is a frequency comb light.
  • the frequency comb light generator 4 1 can use the frequency comb light generator 1 shown in FIG. 1 or 4 or the frequency comb light generator 2 shown in FIG.
  • the frequency comb light generator 41 is controlled by a control signal C from the computer 45.
  • the reference mirror fixed reference mirror 4 3
  • the optical splitter 4 2 (shown as a half-mirror in Fig. 6 (A)) divides the output light (frequency comb light OFC) of the frequency comb light generator 41 into two, and one of them is fixed to the fixed reference mirror 4 3. The light is emitted and the other is emitted toward the object to be measured O.
  • the optical spectroscope 4 2 includes the reflected light R B 1 from the object O to be measured and the reflected light R B 1 from the fixed reference mirror 4 3
  • the frequency comb light generator 41 changes the comb interval by changing the applied modulation signal (RF in Fig. 2 (A), (B), RF 1, RF 2 in Fig. 3 (A), etc.)
  • the observation depth of the measurement target O can be adjusted.
  • the frequency comb light OFC is ⁇ , as shown in the spectrum diagram of Fig. 6 (B). Is the central angular frequency, and there are two ( ⁇ —1) ( ⁇ is an odd number) at the comb spacing ⁇ on the higher and lower frequencies (same as Fig. 2 (C), ⁇ Frequency comb force S of the book (distributed in the band of S ( ⁇ -1) ⁇ ).
  • Figure 6 In the spectrum diagram of B), the intensity of each frequency component is shown to be uniform. In practice, the intensity may vary, but this variation does not significantly affect the detection by the photodiode 44.
  • the electric field e (t) of the output light of the frequency comb light generator 41 is expressed by the following equation (6).
  • the output light of the frequency comb light generator 4 1 (frequency comb light OFC) is transmitted through the optical splitter 42, reflected by the object to be measured O, reflected by the optical splitter 42, and reflected by the photodiode 4 4 ⁇ J (the frequency comb light ⁇ FC is reflected by the measurement target ⁇ and the path reaching photo diode 44 is referred to as “first path pth J”).
  • the output light of this generator 41 (this frequency comb light 0 FC) is reflected by the optical splitter 4 2, further reflected by the fixed reference mirror 4 3, and transmitted through the optical splitter 4 2.
  • the time until reaching Todaio de 4 4 and 2 (the frequency comb light OFC is reflected by the fixed reference mirror 4 3 photodiode 4 a path that reaches the 4 "second path pth 2 ”).
  • ⁇ and ⁇ are the proportions of light in the first and second paths.
  • the photocurrent flowing through the photodiode 44 is the light intensity
  • the photodiode 44 used here has a slow response speed. That is, the photodiode 44 does not respond to the angular frequency of the frequency comb light OFC. Therefore, the output of photo diode 4 4 is the time average of I ei (t) + e 2 (t)
  • n is the refractive index of the optical path medium
  • c is the speed of light
  • the shape of sin has a sharp peak at an integral multiple of 2 ⁇ with ⁇ ⁇ as a variable.
  • the optical path length from the optical splitter 4 2 to the reflection point of the measurement object ⁇ (the reflection point of the frequency comb light OFC inside the measurement object ⁇ ) is measured from the L 1 optical splitter 4 2 to the fixed reference mirror 4 3
  • m integer
  • V RF Frequency spacing of frequency comb light ⁇ ⁇ ⁇ ⁇ ⁇
  • v RF Frequency comb light OFC frequency spacing
  • v When RF is changed in steps of 1 MHz in the range of 8 GHz to 12 GHz, for example, AL 'is about 6 mm. Therefore, the object to be measured O has a resolution of 1 to a depth of 6 mm. It can be measured at 5 ⁇ m.
  • a first embodiment (optical coherence tomography) of the shape measuring apparatus of the present invention will be described with reference to FIG.
  • the optical coherence 'tomodafi 5' in Fig. 8 realizes the optical coherence 'tomography in Fig. 6 (A) from the spatial interference system.
  • a half mirror 53 is used as the optical splitter.
  • the frequency comb light generator 51 includes a frequency comb light generator 1 shown in FIG. 1 or FIG. 4, a frequency comb light generator 2 shown in FIG. 5, and a frequency comb shown in FIG. A light generator 7 can be used.
  • the frequency comb light OFC emitted from the frequency comb light generator 51 is collimated by the condenser lens 52 and emitted to the half mirror 53.
  • the half mirror 5 3 divides the light incident from the condenser lens 52 into two parts, emits one toward the object to be measured O via the variable focus lens 54, and the other as a fixed reference mirror 5 5 To exit.
  • the half mirror 5 3 also reflects the reflected light RB 1 from the reflection point of the measurement target O (the frequency comb light ⁇ FC reflection point inside the measurement target O) and the reflection from the fixed reference mirror 55
  • the light RB 2 is combined and output to the light detector 57 and the image sensor 58.
  • the frequency comb light generator 51 is controlled by a control signal C 1 from a computer 59
  • the variable focus lens 54 is controlled by a control signal C 2 from a computer 59.
  • the optical detector 5 7 receives the output light of the frequency comb light generator 51 (this frequency comb light 0 FC) at the object to be measured O.
  • the light that is reflected and reaches the image sensor 58 (the first path pth J) and the output light of the frequency comb light generator 51 are reflected by the fixed reference mirror 55 and reflected to the image sensor 58. reached by detecting interference between light paths ( "second path pth 2"), the image sensor 5 8 can be detected by the image sensor-5 8 light from the first path pt.
  • L l be the optical path length from the half mirror 5 3 to the reflection point of the measurement target O (the reflection point of the frequency comb light OFC inside the measurement target O), and the fixed reference mirror 5 from the half mirror 5 3
  • L 2 be the optical path length up to 5.
  • This distance difference is inversely proportional to the comb interval ⁇ . Therefore, by controlling the interval of the comb interval ⁇ from the computer 59 (by changing the modulation signal RF), it is possible to start from an arbitrary point inside the measured object O. Interference due to the reflected light can be detected. At this time, the focal length of the variable focus lens 54 is controlled in synchronization with the scanning with the comb interval ⁇ .
  • optical coherence tomography 5 of the present embodiment Since the optical coherence tomography 5 of the present embodiment has no moving parts, the manufacturing cost can be reduced and the reproducibility is also excellent. Finally, the tomographic image data can be obtained by the image sensor 58 and displayed on a display (not shown) of the computer 59.
  • a second embodiment (optical coherence tomography) of the shape measuring apparatus of the present invention will be described with reference to FIG.
  • the optical coherence tomography 6 in FIG. 8 is to realize the optical coherence tomography of the first embodiment by using an optical fiber.
  • a frequency comb light generator 61, an optical fiber splitter 62, A probe lens 6 3, a fixed reference mirror 6 4, a detection lens 6 5, a photodetector 6 6, and a comparator 6 7 are provided.
  • an avalanche photodiode can be used as the photodetector 6 6.
  • the frequency comb light generator 61 is controlled by the control signal C from the computer 67.
  • the frequency comb light OFC output from the frequency comb light generator 61 propagates through the optical fiber F 6 and is divided into two by the optical fiber splitter 62. One is the end of the fiber F 6 (polarization maintaining fiber).
  • the light is reflected by the fixed reference mirror 6 4, and is converted by the optical fiber splitter 6 2 into light that propagates the optical fiber F 6 toward the detection lens 65. This converted light is incident on the photodetector 66 through the detection lens 65.
  • the other half of the light divided by the optical fiber splitter 62 is emitted to the measurement object 0 through the probe lens 63.
  • the reflected light from the object to be measured 0 enters the optical fiber F 6 and enters the photodetector 66 through the detection lens 65.
  • optical coherence tomography 6 in Fig. 9 is basically the same as that of optical coherence tomography 5 in Fig. 6 (A). is there.
  • FIG. 10 is a diagram showing a frequency comb light generator that can also be used in the above-described optical coherence tomography.
  • the frequency comb light generator 7 includes a laser light source 7 1, an isolator 7 2, and an optical resonator 7 3.
  • the laser light source 7 1 can output a single laser beam (center angular frequency ⁇ ) in a wavelength band with high transmittance in the living body, and by inputting the modulation signal L ⁇ , the central angle of the output light Frequency ⁇ .
  • the width can be increased.
  • the isolator 7 2 is provided between the laser light source 7 1 and the optical resonator 7 3, and the laser light source 71 is connected to the first port ⁇ 7 1.
  • the optical resonator 7 3 is connected to the second port P 7 2 via the optical fiber F 7 2 (polarization maintaining fiber).
  • the laser light source 7 1 is a laser with a wavelength band (for example, 1.2 to 1.6 zm) with high transmittance in the living body, similar to the laser light source 1 1 in FIGS. 1 and 4 and the laser light source 2 1 in FIG.
  • Light (center angular frequency ⁇ 0 ) can be output, and by inputting the modulation signal LM, the center angular frequency ⁇ of the output light.
  • the isolator 7 2 is provided between the laser light source 7 1 and the optical resonator 7 3, and the laser light source 7 1 is connected to the optical fiber F 7 1 (polarization) in the first port ⁇ 7 1.
  • the optical resonator 73 is connected to the second port ⁇ 7 2 via the optical fiber F 7 2 (polarization maintaining fiber).
  • the optical resonator 7 3 is a single-loop optical resonator that generates frequency-comb optical OFC using the laser light (center angular frequency ⁇ 0) output from the laser light source 3 1 as a seed.
  • Optical coupler 7 3 1, optical fiber loop 7 3 2, optical modulator 7 3 3 with the same configuration as optical modulator 1 3 1 in Figs. 2 () and (), and optical fiber amplifier 7 3 and 4 are provided.
  • Part of the light incident on the optical fiber loop 7 3 2 is shifted by the optical modulator 7 3 3 by the comb frequency ⁇ , and becomes the light of the angular frequency (of soil ⁇ ).
  • This light circulates in the optical fiber loop 7 3 2 and returns to the polarization maintaining optical coupler 7 3 1.
  • a part of the light of the angular frequency ( ⁇ . Earth ⁇ ) receives the frequency shift by the optical modulator 7 3 3 and becomes the light of the angular frequency ( ⁇ . ⁇ 2 ⁇ ).
  • the optical fiber amplifier 7 3 4 compensates for the light loss in the optical fiber loop 7 3 2, so that the light circulating around the optical fiber loop 7 3 2 is not weakened.
  • frequency comb light is used as light source light, and the following effects can be obtained.
  • the shape measuring method and shape measuring apparatus of the present invention are applied to an optical coherence
  • the frequency comb light generated by the frequency comb light generator is much higher in intensity than the light generated by the conventional low coherence light source, so the light utilization efficiency can be increased. High-accuracy observations at deep depths that were impossible with conventional optical coherence tomography are now possible.
  • a frequency comb light generator is used instead of a low coherence light source (see reference numeral 8 1 in FIG. 11 (A)).
  • the frequency interval of the frequency comb is made variable, so that it is possible to observe the epidermis and the like up to a deep location and with a high depth spatial resolution.
  • the depth spatial resolution is about 10 m.
  • the optical wavelength is about 1.0 nm for a laser beam having a center wavelength of 1.3; am. This can improve the depth spatial resolution to 5 ii m.
  • the shape measuring method and the shape measuring apparatus of the present invention have significantly improved performance compared to the conventional case.
  • Solve various problems eg, large size, high price
  • the shape measuring method and shape measuring device of the present invention can be applied not only to optical coherence tomography but also to a general fine shape measuring device.
  • the distance between the mirrors of the optical resonator can be made sufficiently long by using one optical fiber. Therefore, since the resonant frequency interval is reduced, the frequency interval of the frequency comb can be made variable.
  • the frequency comb light generator according to the present invention uses a fiber amplifier as necessary, it is possible to detect reflected light (signal light) from a highly scattered object with a high S / N ratio.

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Abstract

L’invention concerne un procédé de mesure de forme et un dispositif de mesure de forme capables d'observer une partie profonde sous l'épiderme ou partie similaire avec une haute résolution spatiale. L’invention décrit également un dispositif générateur de lumière à peigne de fréquence capable de faire varier l'intervalle de fréquence et de générer de nombreux peignes de fréquence par une configuration simple et ayant un fonctionnement stable. Le dispositif générateur de lumière à peigne de fréquence inclut une source de lumière laser (11), un résonateur optique (13), un ajusteur d'intervalle de peigne (14) et une ouverture d’émission (OUT). Le dispositif de mesure de forme inclut un interféromètre optique pour mesurer une distance. Le résonateur optique (13) présente un modulateur optique (131), un premier miroir (M11), une fibre optique (F13) séparée de l'autre extrémité d'un guide d'onde optique du modulateur optique et un second miroir (M12). L'ajusteur d'intervalle de peigne (14) est un générateur de signal modulé pour modifier un signal modulé. La fibre optique (F13) présente un dispositif pour compenser le changement de l'état de polarisation (miroir de rotation de Faraday).
PCT/JP2005/015309 2004-08-18 2005-08-17 Procédé de mesure de forme, dispositif de mesure de forme et dispositif générateur de lumière à peigne de fréquence WO2006019181A1 (fr)

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JP2006531931A JP4543180B2 (ja) 2004-08-18 2005-08-17 形状測定方法、形状測定装置および周波数コム光発生装置
DE112005001980T DE112005001980T5 (de) 2004-08-18 2005-08-17 Verfahren und Vorrichtung zur Gestaltmessung, sowie Frequenzkammlichtgenerator
US11/659,951 US7440112B2 (en) 2004-08-18 2005-08-17 Method and an apparatus for shape measurement, and a frequency comb light generator

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JP2004-238902 2004-08-18
JP2004238902 2004-08-18

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EP1870028A1 (fr) * 2006-06-23 2007-12-26 OPTOPOL Technology Spolka z o.o. Appareil et procédé pour la tomographie en cohérence optique dans le domaine de fréquence
EP1870029A1 (fr) * 2006-06-23 2007-12-26 OPTOPOL Technology Spolka z o.o. Appareil et procédé pour la tomographie en cohérence optique dans le domaine de fréquence
WO2007148310A3 (fr) * 2006-06-23 2008-03-06 Optopol Technology Spolka Akcy Appareil de tomographie dans le domaine des frÉquences optiques muni d'un systÈme de rÉglage, systÈme de rÉglage pour appareil de tomographie dans le domaine des frÉquences optiques, procÉdÉ de rÉglage d'un appareil de tomographie dans le domaine des frÉquences optique
WO2008090599A1 (fr) * 2007-01-22 2008-07-31 School Juridical Person Kitasato Institute Appareil de tomographie de cohérence optique
JP2009025245A (ja) * 2007-07-23 2009-02-05 Optical Comb Inc 光干渉観測装置
JP2009025202A (ja) * 2007-07-20 2009-02-05 National Institute Of Information & Communication Technology 光干渉トモグラフィー装置，光形状計測装置
WO2010001809A1 (fr) * 2008-07-03 2010-01-07 株式会社光コム Télémètre, procédé de télémétrie et dispositif optique de détermination de forme tridimensionnelle
JP2010122043A (ja) * 2008-11-19 2010-06-03 Nikon Corp 低コヒーレンス干渉計、低コヒーレンス干渉装置、及び低コヒーレンス干渉測定方法
WO2010119562A1 (fr) * 2009-04-17 2010-10-21 Koyama Naoyuki Procédé et dispositif de télémétrie laser
WO2010131337A1 (fr) * 2009-05-13 2010-11-18 Koyama Naoyuki Procédé de télémétrie laser et dispositif de télémétrie laser
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JP2010261890A (ja) * 2009-05-11 2010-11-18 Canon Inc 光波干渉計測装置
JP2011027649A (ja) * 2009-07-28 2011-02-10 Optical Comb Inc 位置決め装置及び位置決め方法
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EP1870029A1 (fr) * 2006-06-23 2007-12-26 OPTOPOL Technology Spolka z o.o. Appareil et procédé pour la tomographie en cohérence optique dans le domaine de fréquence
WO2007148310A3 (fr) * 2006-06-23 2008-03-06 Optopol Technology Spolka Akcy Appareil de tomographie dans le domaine des frÉquences optiques muni d'un systÈme de rÉglage, systÈme de rÉglage pour appareil de tomographie dans le domaine des frÉquences optiques, procÉdÉ de rÉglage d'un appareil de tomographie dans le domaine des frÉquences optique
EP1870030A1 (fr) * 2006-06-23 2007-12-26 OPTOPOL Technology Spolka z o.o. Appareil et procédé pour la tomographie en cohérence optique dans le domaine de fréquence
US8570525B2 (en) 2006-06-23 2013-10-29 Optopol Technology S.A. Apparatus for optical frequency domain tomography with adjusting system
US7940398B2 (en) 2007-01-22 2011-05-10 School Juridical Person Kitasato Institute Optical coherence tomography apparatus
WO2008090599A1 (fr) * 2007-01-22 2008-07-31 School Juridical Person Kitasato Institute Appareil de tomographie de cohérence optique
JPWO2008090599A1 (ja) * 2007-01-22 2010-05-13 学校法人北里研究所 オプティカル・コヒーレンス・トモグラフィー装置
JP2009025202A (ja) * 2007-07-20 2009-02-05 National Institute Of Information & Communication Technology 光干渉トモグラフィー装置，光形状計測装置
JP2009025245A (ja) * 2007-07-23 2009-02-05 Optical Comb Inc 光干渉観測装置
WO2010001809A1 (fr) * 2008-07-03 2010-01-07 株式会社光コム Télémètre, procédé de télémétrie et dispositif optique de détermination de forme tridimensionnelle
JP2010014549A (ja) * 2008-07-03 2010-01-21 Optical Comb Inc 距離計及び距離測定方法並びに光学的三次元形状測定機
JP2010122043A (ja) * 2008-11-19 2010-06-03 Nikon Corp 低コヒーレンス干渉計、低コヒーレンス干渉装置、及び低コヒーレンス干渉測定方法
WO2010119562A1 (fr) * 2009-04-17 2010-10-21 Koyama Naoyuki Procédé et dispositif de télémétrie laser
JP2010261776A (ja) * 2009-05-01 2010-11-18 Canon Inc 光波干渉計測装置
JP2010261890A (ja) * 2009-05-11 2010-11-18 Canon Inc 光波干渉計測装置
WO2010131339A1 (fr) * 2009-05-13 2010-11-18 Koyama Naoyuki Procédé de télémétrie laser et dispositif de télémétrie laser
WO2010131338A1 (fr) * 2009-05-13 2010-11-18 Koyama Naoyuki Procédé de télémétrie laser et dispositif de télémétrie laser
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JP2011027649A (ja) * 2009-07-28 2011-02-10 Optical Comb Inc 位置決め装置及び位置決め方法
JP2012154728A (ja) * 2011-01-25 2012-08-16 Tokyo Univ Of Agriculture & Technology 構造測定方法および構造測定装置
WO2014156436A1 (fr) * 2013-03-29 2014-10-02 株式会社日立ハイテクノロジーズ Dispositif et système de mesure de déplacement

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DE112005001980T5 (de) 2007-07-12
US7440112B2 (en) 2008-10-21

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